Re: Miniature mechanical trigger ideas needed?

From: John Nagle (nagle_at_animats.com)
Date: 01/06/05 

Date: Thu, 06 Jan 2005 06:12:15 GMT

CWatters wrote:

> <kurtsutherland@comcast.net> wrote in message
> news:1104901239.606342.111930@z14g2000cwz.googlegroups.com...
>
>>I am looking for a miniature trigger to release a small compression or
>>torsional spring that as about 1 lbf of force at full compression.

    One of the more elegant solutions is to use something
made from a "memory metal" alloy. When you run a current
through it, it deforms, and when it cools, it goes back
to normal.

See

    http://www.robotstore.com/catalog/display.asp?pid=2

Shape-memory alloys have been a solution looking for
a problem for decades. Minature electrically-released
latches are one of the few good applications.

Back in the 1980s, someone at Stanford built a Frisbee
which could be shot down with a laser tag gun.
It used a shape-memory alloy latch to hold down
a fin. When a laser beam hit the sensor, current
flowed through the latch, which deformed and
released the fin. The fin acted as a speed brake
and caused the Frisbee to crash. Neat idea,
too expensive back then.

                        John Nagle

Relevant Pages

  • Re: Miniature mechanical trigger ideas needed?
    ... >>torsional spring that as about 1 lbf of force at full compression. ... Shape-memory alloys have been a solution looking for ... It used a shape-memory alloy latch to hold down ... released the fin. ...
    (sci.electronics.misc)
  • Re: real-time compression algorithms on fpga
    ... I forgot to mention that I want my compression scheme to be lossless and not ... > decompress(FILE *fin, FILE *fout) ...
    (comp.compression)